Liquefaction of Lignocellulosic Wastes by Using Ethylene Carbonate Solvent: The Effect of Process Variables on Properties

Ethylene Carbonate (EC) was selected as a new solvent in order to establish a rapid liquefaction technique converting lignocellulosic waste into useful chemicals. Beechwood sawdust was liquefied by using Ethylene Carbonate (EC) as a solvent and sulfuric acid as a catalyst at high temperatures (110-160°C) and at three times (20, 40, 60 minutes) for the preparation of suitable polyol. After the liquefaction process at different temperatures and times and investigation of characterization of hydroxyl number, acid number, and yield of polyol were seen that the temperature of 130°C was an appropriate temperature for the production of polyol. Then in order to determine the appropriate time for producing the polyol at this temperature, the liquefaction process was continued at different times (40, 60, 90, 120, and 180 min) which as a result 120 minutes being selected as an appropriate time for the preparation of polyol. Also, the results showed that with increasing the temperature and time of liquefaction, the acid number and yield, and viscosity were increased, but hydroxyl number was reduced. The FTIR spectroscopy analysis showed the existence of the hydroxyl groups (OH) in the liquefied Beech sawdust (polyol) and confirmed that wood sawdust is a source of bio polyols. Also, it can be concluded that bio polyol is suitable for the preparation of polymeric products, including polyurethane adhesive. Statistical analysis showed that variation of hydroxyl and acid number, yield, and viscosity have a significant difference with increasing at temperature and time.